Off-Earth materials and ISRU

When, and whether, lunar, asteroidal or Martian materials become part of rotating stations.

Key results

• Near-term stations are built from Earth materials. Coastal Ron: ISRU is not near-term Coastal Ron, 2023-09-18; lunar exports are generations away Coastal Ron, 2022-11-27. Earth is the primary supplier: ship coil sheet stock and form it in space Coastal Ron, 2022-11-27.
• Large stations need shielding from off-Earth mass.
• Large AG habitats can't live in LEO long (drag) and need passive shielding, which means ISRU mikelepage, 2015-02-22.
• A 1 km station needs ~6 Mt of shielding lamontagne, 2022-11-27. JohnFornaro's ring would need 3300 flights with lunar material against 20,000 without lamontagne, 2022-10-13.
• mikelepage: passive shielding must come from asteroids mikelepage, 2023-09-15.
• Lunar materials.
• Ilmenite yields Fe and Ti (McKay et al. NASA SP-509), with slag as shielding JohnFornaro, 2022-10-17; JohnFornaro, 2023-01-08.
• Lunar Fe and Cr exist for stainless lamontagne, 2022-11-10.
• Lunar anhydrous glass hulls lamontagne, 2022-12-15. "FeRe" (lunar Fe + regolith) formed in a construction shack or cast JohnFornaro, 2023-06-09.
• The Moon is poor in C, H and N lamontagne, 2022-10-06. Lunar carbon (arXiv 2104.13521) JohnFornaro, 2022-10-06.
• Delivery: mass drivers and nuclear maglev launchers to EML-1 JohnFornaro, 2023-04-27; lamontagne, 2022-10-18. Mass launchers need circularization and catching Coastal Ron, 2022-11-27. SpinLaunch payloads are <200 kg, and $170/t Moon→L5 is implausible LMT, 2024-03-20.
• Concrete ISRU on the Moon A_M_Swallow, 2015-09-04.
• Asteroids.
• mikelepage's asteroid-pit bola, and a pedestal at an asteroid's pole mikelepage, 2023-09-15; mikelepage, 2024-01-31.
• Asteroid networks: 3–15 year transit windows; targets are likely not NEOs (they need water for propellant) mikelepage, 2023-10-03.
• 2008 EQ → Psyche window once per 35 years LMT, 2023-09-15. ISRU monopropellant doubles as shield ("burn shield on arrival") LMT, 2023-09-15.
• SEP-delivered NEA samples for an industry demonstrator KelvinZero, 2022-11-01. Asteroid bagging (TransAstra) JohnFornaro, 2022-11-27.
• A structural analysis of a 0.38 g cavern in a spinning asteroid (Frontiers 2019) Lampyridae, 2022-09-09.
• A regolith 3D-printing probe; a nautilus-shell regolith-cell settlement mikelepage, 2015-02-22; mikelepage, 2022-09-09.
• Mars.
• LMT's "Red Gold": FeNi smelter waste turned into 3 mm plates; 50 t per returning Mars Starship = 2220 m² LMT, 2023-01-07.
• Mars chromite LMT, 2023-01-08. Phobos and Deimos may lack water lamontagne, 2024-03-20.
• Atmosphere trawling. O₂/N₂ trawled from the thermosphere (ASCENT, EVLEO) LMT, 2023-01-07; LMT, 2023-01-14.
• Manufacturing constraints.
• High-strength parts (Ti, UHMWPE) need big factories Coastal Ron, 2015-10-08.
• Self-replicating factories are needed for colonies to pay lamontagne, 2023-01-28; lamontagne, 2023-01-07.
• Energy at $0.01/kWh and 1000× cost drops are assumed for settlements lamontagne, 2024-03-20.
• 1 g stations enable ISRU. A 1 g station allows conventional terrestrial machinery, making ISRU cheaper daveklingler, 2015-10-13. Separation processes work better in gravity lamontagne, 2023-10-02.

Open questions

• Which comes first at scale: lunar shielding mass, asteroidal water/metal, or thermospheric gases?
• At what station size does ISRU shielding beat Earth-launched polyethylene?

Related pages

• Materials · Radiation shielding · Growth and staging · Location

Sources

Forum posts

• mikelepage, 2015-02-22 (reply #363): Large habitats need ISRU. Post.
• A_M_Swallow, 2015-09-04 (reply #619): Lunar concrete. Post.
• Coastal Ron, 2015-10-08 (reply #683): Big factories needed. Post.
• daveklingler, 2015-10-13 (reply #697): 1 g allows terrestrial machinery. Post.
• mikelepage, 2022-09-09 (reply #1781, 1 like): Nautilus settlement. Post.
• Lampyridae, 2022-09-09 (reply #1782): Spinning asteroid cavern. Post.
• JohnFornaro, 2022-10-06 (reply #1875, 1 like): Lunar carbon. Post.
• lamontagne, 2022-10-06 (reply #1878): Moon poor in C, H, N. Post.
• lamontagne, 2022-10-13 (reply #2068, 1 like): Lunar material saves flights. Post.
• JohnFornaro, 2022-10-17 (reply #2123): Ilmenite; slag shielding. Post.
• lamontagne, 2022-10-18 (reply #2127, 1 like): Mass driver equations. Post.
• KelvinZero, 2022-11-01 (reply #2295, 2 likes): NEA samples. Post.
• lamontagne, 2022-11-10 (reply #2355): Lunar Fe & Cr. Post.
• lamontagne, 2022-11-27 (reply #2464, 1 like): ~6 Mt shielding. Post. Attachments: DeltaV map.png, Station (2).xlsx.
• JohnFornaro, 2022-11-27 (reply #2465): TransAstra. Post. Attachments: Ring-SK-009-Solar-Thermal-Rocket-Concept.jpg, Ring-SK-010-Orbits-&-Parabola.jpg, Ring-SK-009-Solar-Thermal-Rocket-Concept.pdf, Ring-SK-010-Orbits-&-Parabola.pdf.
• Coastal Ron, 2022-11-27 (reply #2466): Lunar exports generations away. Post.
• Coastal Ron, 2022-11-27 (reply #2469): Ship sheet stock. Post.
• lamontagne, 2022-12-15 (reply #2656): Soilleux lunar glass. Post. Attachments: JBIS-v72-no07-July-2019_f838tt.pdf.
• lamontagne, 2023-01-07 (reply #2791): i4is Principium. Post. Attachments: The-Self-Replicating-Factory-a-work-in-progress-Principium33-print-2105280923.pdf, srf.png.
• LMT, 2023-01-07 (reply #2803): Mars FeNi plates. Post. Attachments: Kalpana-24_Ba2-1920.jpg.
• JohnFornaro, 2023-01-08 (reply #2812): Ilmenite feedstock. Post.
• LMT, 2023-01-08 (reply #2823): Mars chromite. Post.
• LMT, 2023-01-14 (reply #2894): 96% trawled O₂/N₂. Post. Attachments: Omaha_Trail_2021.png.
• lamontagne, 2023-01-28 (reply #3144, 2 likes): Self-replicating factories. Post. Attachments: Kalpana greenhouse.jpg.
• JohnFornaro, 2023-04-27 (reply #3646): Nuclear maglev launcher. Post.
• JohnFornaro, 2023-06-09 (reply #3819): FeRe. Post. Attachments: Ring-SK-204-Assembly-Sequence-III.jpg, Ring-SK-204-Assembly-Sequence-III.pdf.
• mikelepage, 2023-09-15 (reply #3943): Passive from asteroids. Post.
• LMT, 2023-09-15 (reply #3945): Psyche window. Post.
• Coastal Ron, 2023-09-18 (reply #3966): ISRU not near-term. Post.
• lamontagne, 2023-10-02 (reply #4099, 3 likes): Separation in gravity. Post. Attachments: Armstrong1.jpg, Armstrong factory3.jpg.
• mikelepage, 2023-10-03 (reply #4122): Asteroid network. Post.
• mikelepage, 2024-01-31 (reply #4450): Asteroid pedestal. Post.
• LMT, 2024-03-20 (reply #4595): SpinLaunch limits. Post.
• lamontagne, 2024-03-20 (reply #4596): Phobos/Deimos water. Post.

External references

• McKay, D. et al. (1992). Space Resources, NASA SP-509.
• Soilleux, R. (2019). JBIS 72(7).
• Frontiers (2019), structural analysis of a 0.38 g cavern in a spinning asteroid.